package com.hao.netty.chapter02.nio;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.Set;
import java.util.Date;

/**
 * @Description //TODO
 * @Date 2020/1/11
 * @Author songhao
 **/
public class TimeClientHandler implements Runnable {

    private String host;
    private int port;
    private Selector selector;
    private SocketChannel socketChannel;
    private volatile boolean stop;

    public TimeClientHandler(String host, int port) {
        this.host = host == null ? "127.0.0.1" : host;
        this.port = port;
        try{
            selector = Selector.open();
            socketChannel = SocketChannel.open();
            socketChannel.configureBlocking(false);
        }catch (Exception e){
            e.printStackTrace();
            System.exit(-1);
        }
    }

    @Override
    public void run() {
        try{
            //第一步进行连接
            doConnect();
        }catch (Exception e){
            e.printStackTrace();
            System.exit(-1);
        }
        while(!stop){
            try{
                System.out.println(new Date(System.currentTimeMillis()));
                selector.select(1000);
                Set<SelectionKey> selectionKeys = selector.selectedKeys();
                Iterator<SelectionKey> it = selectionKeys.iterator();
                SelectionKey key = null;

                while(it.hasNext()){
                    key = it.next();
                    it.remove();
                    try{
                        handleInput(key);
                    }catch (Exception e){
                        e.printStackTrace();
                        if(key != null){
                            key.cancel();
                            if(key.channel() != null){
                                key.channel().close();
                            }
                        }
                    }
                }
            }catch (Throwable e){
                e.printStackTrace();
            }
        }

        if(selector != null){
            try{
                selector.close();
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    private void handleInput(SelectionKey key) throws IOException {
        if(key.isValid()){
            System.out.println("进入事件处理了--- " + key.isConnectable());
            SocketChannel sc = null;
            try{
                //判断是否链接成功
                sc = (SocketChannel)key.channel();
                if(key.isConnectable()){
                    System.out.println("---- 连接状态:" + sc.finishConnect());

                    if(sc.finishConnect()){
                        System.out.println("客户端连接服务器了成功...");
                        sc.register(selector,SelectionKey.OP_READ);
                        doWrite(sc);
                    }else{
                        System.out.println("客户端连接服务器失败了...");
                        //链接失败，进程退出
                        System.exit(-1);
                    }
                }
            }catch (Exception e){
                System.out.println("客户端连接服务器失败了...");
                //链接失败，进程退出
                System.exit(-1);
            }

            if(key.isReadable()){
                ByteBuffer readBuffer = ByteBuffer.allocate(1024);
                int readBytes = sc.read(readBuffer);
                if(readBytes > 0) {
                    readBuffer.flip();
                    byte[] bytes = new byte[readBuffer.remaining()];
                    readBuffer.get(bytes);
                    String body = new String(bytes, "UTF-8");
                    System.out.println("Now is : " + body);

                    //this.stop = true;
                }else if(readBytes < 0){
                    //对端链路关闭
                    System.out.println("服务端已关闭...");
                    key.cancel();
                    sc.close();
                }else{
                    System.out.println("未读取到内容,0字节");
                }
            }
        }
    }

    private void doConnect() throws IOException{
        //如果直接连接成功，则注册到多路复用器上，发送请求消息，读应答
        if(socketChannel.connect(new InetSocketAddress(host,port))){
            //连接上了就注册读取事件
            socketChannel.register(selector,SelectionKey.OP_READ);
            doWrite(socketChannel);
        }else{
            //未连接上就注册连接事件
            socketChannel.register(selector,SelectionKey.OP_CONNECT);
        }
    }

    private void doWrite(SocketChannel sc) throws IOException{
        byte[] req = "QUERY TIME ORDER".getBytes();
        ByteBuffer writeBuffer = ByteBuffer.allocate(req.length);
        writeBuffer.put(req);
        writeBuffer.flip();
        sc.write(writeBuffer);
        if(!writeBuffer.hasRemaining()){
            System.out.println("Send order 2 server succeed.");
        }
    }

}
